1. Field of the Invention
The present invention relates to a mouthpiece of flute, and more particularly, to a mouthpiece of flute which is capable of easily giving a clear, vigorous, rich and loud sound and by means of which high-pitched tones of the scale of the flute can be obtained easily.
2. Description of the Prior Art
The present inventor has already studied and invented a mouthpiece of flute which is so designed as to be able to obtain a rich and good sound quality by dividing the interior space of a pipe into two parts including an acoustic space and a fluid space by forming a projective tongue portion without fail.
More specifically, in a mouthpiece 2a shown in FIG. 4, a continuous inner surface region extending from an edge 4a through the inner surface of a hole 3a to the upper portion of an inner surface 5a of a head pipe 1a is so formed as to be a streamlined surface 6a in order to make a laminar flow that is freed from any turbulent flow, and the inner surface of the hole 3a on this side on which a lip is to be put is made to extend downward into the head pipe 1a so as to form on the inner wall of the head pipe 1a a projective tongue portion 11a having the lower surface of which is formed by a concaved curved surface 12a, so that the interior space of the pipe is divided into two parts including an acoustic space A and a fluid space B.
An exhalation 7a sent forth through the gap between the lips is made to blow against the edge 4a and is therefore divided into halves as indicated by an inside vector 8a and an outside vector 9a. The air stream indicated by the inside vector 8a is made to flow along the edge 4a, the streamlined surface 6a and the inner surface 5a of the pipe in the mentioned order. Then, it is noted that a sound is produced when the air blown against the edge 4a vibrates in the vertical direction in the acoustic space A. Namely, the streamline indicated by the inside vector 8a becomes a laminar flow without forming any turbulent flow, and moreover, this flow swirls along the concaved curved surface 12a of the projective tongue portion 11a within the head pipe 1a so as to become a helical flow which in turn runs forwardly within the head pipe 1a. Due to this helical flow, an inward inflow vector 10a going from the hole 3 a toward the inner part acts as if it causes a kind of vortex absorption, and this inflow vector 10a flows into a region of the fluid space B located below the projective tongue portion 11a so as to be joined with the helical flow of the inside vector 8a.
In the case of the above-described mouthpiece of flute, however, since the fluid space is expanded outwardly to become a bulging enlarged space, a vortex effect resulting from the helical flow generating in the fluid space is great so that it is indeed possible to obtain a clear, vigorous, rich and loud sound quality sufficiently, but it was found, on the other hand, that the high-pitched tones of the scale of the flute are troubled.
Further, the hole of the mouthpiece is provided with what is called undercut so as to be formed in a divergent nozzle-like tapered hole having the diameter of which is increased gradually from the outer open end to the inner open end, so that it is possible to give a rich and loud sound. However, it was found that if the degree of taper of this undercut is made large excessively it becomes impossible to give the highest-pitched tone as is the case of the above-described enlarged space.
In the above-described mouthpiece of flute, however, since the inner surface of the hole 3a on this side is made to extend downward into the head pipe 1a so as to form on the inner wall of the head pipe 1a the projective tongue portion 11a the lower surface of which is formed by the concaved rounded surface 12a, the interior space of the head pipe 1a is narrowed by the projective tongue portion 11a. Since the fluid space B is narrowed in particular, the function of joining the inflow vector 10a with the inside vector 8a within the fluid space B is not sufficient, resulting in that the vortex effect due to which the resistance to exhalation is reduced is deteriorated, thereby making it impossible to obtain a clear, vigorous and rich sound quality satisfactorily.
To cope with this, the present inventor has studied and invented another mouthpiece of flute which is capable of eliminating the above-described problems.
More specifically, in a mouthpiece of flute shown in FIG. 5, a projective tongue portion 11a is provided in such a manner that, in a position where the inner surface of a hole 3a on this side on which a lip is to be put meets the inner surface of a head pipe 1a, a bulgy rounded concaved surface 12a is formed so as to be made to bulge outwardly of the head pipe 1a, and the interior space of the pipe 1a is divided into two parts including an acoustic space A and a fluid space B.